铁锌共掺杂MCM-41构建双酸性中心及其催化臭氧化布洛芬

Dual acidity centers constructed by Fe and Zn co-doped MCM-41 for catalytic ozonation of ibuprofen

Fe-MCM-41作为臭氧(O_(3))催化剂被广泛关注,但其存在O_(3)利用率和界面反应效率较低等缺点,这极大限制了其在非均相催化臭氧化领域的应用。为解决这一问题,通过一步水热合成方法制备了具有双酸性中心的Fe-Zn-MCM-41催化剂。不同臭氧化体系对布洛芬(IBP)降解结果表明,反应30 min后Fe-Zn-MCM-41/O_(3)降解IBP的表观速率常数为0.035 min^(−1),分别是单独O_(3)、MCM-41/O_(3)、Fe-MCM-41/O_(3)和Zn-MCM-41/O_(3)的2.9、2.9、1.9和1.6倍。XRD、N_(2)吸附-脱附、TEM和XPS等表征结果证明,Fe和Zn成功进入MCM-41骨架内并分别作为中酸位点和强酸位点。中酸位点产生的·OH迅速扩散到溶液中,加快溶液中IBP的去除;强酸位点产生的·OH键合在Fe-Zn-MCM-41表面,促进IBP界面氧化。LSV和EIS结果表明,Fe-Zn-MCM-41不仅具有较好的电子传递能力,而且拥有较强的O_(3)亲和力。Fe-Zn-MCM-41具有较好的循环使用性能,经过5次回收使用后,Fe-Zn-MCM-41/O_(3)仍可去除55.1%的IBP,去除率远高于其他臭氧化体系。以上研究结果可为非均相催化臭氧化体系在水环境污染控制领域的应用提供参考。

The application of Fe-MCM-41 as O_(3) catalyst had attracted extensive attentions,but the shortcomings such as low O_(3) utilization rate and poor interfacial reaction efficiency greatly limited its further application in heterogeneous catalytic ozonation.To solve these problems,Fe-Zn-MCM-41 with dual acidity centers was prepared through a one-step hydrothermal method.It was found that the apparent rate constant of IBP removal in Fe-Zn-MCM-41/O_(3) was 0.035 min^(−1) after 30 min reaction,which was 2.9,2.9,1.9 and 1.6 times of O_(3) alone,MCM-41/O_(3)、Fe-MCM-41/O_(3) and Zn-MCM-41/O_(3),respectively.XRD,N_(2) adsorption-desorption,TEM and XPS results indicated that Fe and Zn successfully entered the framework of MCM-41 and acted as medium acid sites and strong acid sites,respectively.The medium acid sites produced more·OHfree to accelerate the bulk reaction,and the strong acid sites generated more·OHad bonding on the surface of Fe-Zn-MCM-41 to promote the interfacial reaction.LSV and EIS showed that Fe-Zn-MCM-41 not only possessed a better electron transfer ability,but also had a stronger affinity with O_(3) than others.The IBP removal still could reach 55.1%in Fe-Zn-MCM-41/O_(3) after five recycles,which indicated that Fe-Zn-MCM-41 had a better recycling ability.This work provided a reference for the study of heterogeneous catalytic ozonation and its applications in environmental remediation.